A video frame may be characterized by a multiresolution signal representation. Existing multi-resolution motion estimation schemes find motion vectors in the original image domain using constant block size for block matching, (see, for example, K. M. Uz et al. in "Interpolative Multiresolution Coding of Advanced Television with Compatible Subchannels," IEEE Transactions on Circuits and Systems for Video Technology, Vol.1, No. 1 (March 1991)). In coding applications employing this multiresolution representation, motion estimation is performed by comparing a region being coded in a current frame with regions in a previous frame to compute a displacement vector in accordance with a matching criterion.
An inherent disadvantage is that the motion estimation is unable to detect motion activities for small objects in the lower resolution representations.